Document Type
Article
Publication Date
3-16-2022
Abstract
In this paper, we explore the operation of a nonreciprocal non-Hermitian system consisting of a lossy magneto-optical ring resonator coupled to another ring resonator with gain and loss, and we demonstrate that such a system can exhibit non-reciprocity-based broken parity-time (PT) symmetry and supports one-way exceptional points. The nonreciprocal PT-phase transition is analyzed with the use of both analytical tools based on coupled-mode theory and two-dimensional finite element method simulations. Our calculations show that the response of the system strongly depends on the regime of operation – broken or preserved PT-symmetry. This response is leveraged to show that the system can operate as an optical isolator or a one-way laser with functionality tuned by adjusting loss/gain in the second ring resonator. The proposed system can thus be promising for device applications such as magnetically or even optically switchable non-reciprocal devices and one-way micro-ring lasers.
Comments
This article was originally published in Optical Materials Express, available at https://doi.org/10.1364/OME.450821
This work is published under an Optica Open Access Publishing Agreement.